Method of disabling and locking open a safety valve with releasable flow tube for flapper lockout

Abstract

A safety valve has a lock open feature that is actuated by expanding or penetrating the flow tube to disconnect the link between the piston in the hydraulic control system and the flow tube. In normal operation, downward movement of the piston moves the flow tube against a power spring. When the flow tube is expanded, penetrated, or otherwise altered, the piston no longer acts on the flow tube and the flow tube can be simply pushed down and locked in position with the flapper wide open.

1. A method of disabling and locking open a safety valve, comprising:
 releasing a piston that is connected to a flow tube from said flow tube; 
 shifting the flow tube from within said flow tube so that it opens the flapper; 
 locking the flow tube in position after said shifting. 
 
   
   
     2. The method of  claim 1 , comprising:
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 accomplishing said selectively releasing and said shifting of said flow tube in a single trip downhole. 
 
   
   
     3. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube from within said flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 not compressing a power spring when shifting said flow tube after said selective releasing. 
 
   
   
     4. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 expanding said flow tube to accomplish said selective releasing. 
 
   
   
     5. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube so that it opens the flapper; shifting the flow tube, after said selectively releasing, so that it opens the flapper; penetrating said flow tube to accomplish said selective releasing. 
 
   
   
     6. A method of disabling and locking open a safety valve, comprising:
 releasing a piston that is connected to a flow tube from said flow tube; 
 shifting the flow tube from within said flow tube so that it opens the flapper; 
 locking the flow tube in position after said shifting; 
 springing a lock into position to hold said flow tube as a result of said shifting of said flow tube. 
 
   
   
     7. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 locking the flow tube in position after said shifting; 
 springing a lock into position to hold said flow tube as a result of said shifting of said flow tube; 
 providing a groove in said flow tube; 
 allowing a ring to snap into said groove to lock the position of said flow tube. 
 
   
   
     8. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube from within said flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 providing a connector between said piston and said flow tube; 
 causing said connector to fail. 
 
   
   
     9. The method of  claim 8 , comprising:
 compressing a power spring with said connector when said piston moves and said connector has not yet been caused to fail. 
 
   
   
     10. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube from within said flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 providing a connector between said piston and said flow tube; 
 causing said connector to fail; 
 providing segments held together with at least one fastener as said connector. 
 
   
   
     11. The method of  claim 10 , comprising: shearing said fastener. 
   
   
     12. The method of  claim 11 , comprising: locking the flow tube in position after said shifting. 
   
   
     13. The method of  claim 12 , comprising:
 springing a lock into position to hold said flow tube as a result of said shifting of said flow tube. 
 
   
   
     14. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 providing a connector between said piston and said flow tube; 
 causing said connector to fail; 
 providing segments held together with at least one fastener as said connector; 
 surrounding said flow tube with said segments; 
 surrounding said flow tube with said segments. 
 
   
   
     15. The method of  claim 14 , comprising:
 causing said connector to fail by expansion of said flow tube adjacent said connector. 
 
   
   
     16. The method of  claim 14 , comprising:
 causing said connector to fail by penetration of said flow tube and displacement of at least one of said segments. 
 
   
   
     17. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube; 
 shifting the flow tube so that it opens the flapper; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 providing a connector between said piston and said flow tube; 
 causing said connector to fail; 
 providing segments held together with at least one fastener as said connector; 
 shearing said fastener; 
 locking the flow tube in position after said shifting; 
 springing a lock into position to hold said flow tube as a result of said shifting of said flow tube; 
 providing a groove in said flow tube; 
 allowing a ring to snap into said groove to lock the position of said flow tube. 
 
   
   
     18. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube by expanding the flow tube; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 accomplishing said selectively releasing and said shifting of said flow tube in a single trip downhole; 
 running in a combination expansion and shifting tool to accomplish said releasing and said shifting. 
 
   
   
     19. A method of locking open a safety valve, comprising:
 selectively releasing a piston from a flow tube by penetration through said flow tube; 
 shifting the flow tube, after said selectively releasing, so that it opens the flapper; 
 accomplishing said selectively releasing and said shifting of said flow tube in a single trip downhole; 
 running in a combination penetration and shifting tool to accomplish said releasing and said shifting.